Super PACs are A-OK with Republicans, but they then must-- must-- crush labor unions, because they could actually raise money to promote Democratic candidates. Via the Sunlight Foundation:

Jeffery Scott Bensing, a registered lobbyist and former Chief of Staff to Sen. John Ensign, R-Nev., filed paperwork in January with the Federal Election Commission to create the Freedom Path Action Network, a new independent expenditure only committee. These committees--also known as Super PACs because they can raise unlimited funds from any source and spend it to support or oppose federal candidates--played critical roles in some races in the 2010 mid-term elections.